This is a multidisciplinary program project directed toward (1) relation of the nutritional state of the pregnant woman to development of her fetus; (2) attempting to predict fetal malnutrition in utero by studies of the metabolism of peripheral blood leukocytes of the pregnant woman. The project is essentially biochemical in nature but also provides correlative information with respect to obstetrical, socio- cultural, demographic and nutritional information of the parents, and growth and developmental assessments of the child. Nutritional state is determined by diet history and analysis of nutrients in blood, urine and hair. In addition, studies of fetal-maternal amino acid pools and of placental protein synthesis, and the phagocytic capacities of leukocytes also are being done. Animal investigations are designed to study the effect of diet restriction during pregnancy on the ontogenesis of specific metabolic pathways in fetal organs. The study is carried out in two principal locations: University of Oklahoma Health Sciences in Oklahoma City and Centro Medico Nacional, Instituto Mexicano del Seguro Social, Mexico, D. F. Other participating units are Human Research Laboratories, Grand Forks, North Dakota and Protein Research Laboratories, Beltsville, Maryland, both of the USDA.